Hello @jochemvandrimmelen,
Are your general WordPress emails, for example, the password reset emails also getting to the Spam folder?
If yes, are you using an email SMTP plugin to send your emails? If not, this could be a great option to try. The Branda plugin does have an Email integration plugin through which you can use your SMTP email to be configured so you can use one of your other work emails to work and deliver your site emails. Here is the link for the same: https://www.ads-software.com/plugins/branda-white-labeling/
If you do already have SMTP emails being sent and the emails are still getting to the SPAM folder in both the WordPress password reset and forminator form email delivery cases, You will need to check with your email provider for the same.
Should you have any doubts or need any help, feel free to reply in the thread below and we would be happy to help!
Regards,
Prathamesh Palve